261745729207 has 4 divisors (see below), whose sum is σ = 261777208696. Its totient is φ = 261714249720.

The previous prime is 261745729123. The next prime is 261745729213. The reversal of 261745729207 is 702927547162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261745729207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261745729237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15727269 + ... + 15743902.

It is an arithmetic number, because the mean of its divisors is an integer number (65444302174).

Almost surely, 2^261745729207 is an apocalyptic number.

261745729207 is a deficient number, since it is larger than the sum of its proper divisors (31479489).

261745729207 is an equidigital number, since it uses as much as digits as its factorization.

261745729207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31479488.

The product of its (nonzero) digits is 2963520, while the sum is 52.

The spelling of 261745729207 in words is "two hundred sixty-one billion, seven hundred forty-five million, seven hundred twenty-nine thousand, two hundred seven".